HPV Vaccines

Currently there are vaccines available which act against specific HPV subtypes which cause genital warts, anal cancer, cervical cancer, vaginal cancer and also oral cancers. Gardasil by Merck is a quadrivalent vaccineagainst HPV 16&18 (cancer causing subtypes) and HPV 6&11 (which accounts for 90% genital warts). Cervarix by GSK prevents infection against HPV subtypes 16&18 (accounts for 70% of cervical cancers).

The vaccines are most effective if taken before first sexual intercourse hence it is usually recommended for those age between 9-26. The vaccines do not contain live virus or any HPV DNA hence it neither induces the condition nor cause infections. The vaccines prevent HPV infection BUT do not treat HPV infection.

The vaccines are approved for both males and females. Vaccinating men and women will reduce the HPV virus pool in the community. It is also highly recommended in men who have sex with men (MSM) as they are at higher risk of higher risk for genital warts, penile cancer, and anal cancer.

Newer studies have revealed that HPV vaccines are effective in preventing older women from cervical cancer up to 45 years old. FDA has classified the HPV vaccine as a pregnancy Category B which means there is no apparent harm on the fetus in animal studies. HPV vaccines are currently not recommended for pregnant women as there are no sufficient studies to support its safety or effects on the fetus.

In males, Gardasil that covers 4 subtypes especially those associated with genital cancers are recommended. In females, either one of the vaccines are able to prevent cervical cancers.

The vaccines are injected into the muscles at intervals of 0, 1 or 2 and 6 months. A total of 3 vaccine shots will complete the immunization. Currently there are no data on whether booster jabs are necessary. If a woman is pregnant during the three dose series of vaccination, the series will be postponed until pregnancy has been completed.

The common side effects from the vaccines are soreness at injection site associated with mild swelling. Long term safety effects are still being evaluated.

As the vaccines do not protect against other subtypes that may also cause genital cancers, regular check-ups and pap smears are still recommended. Condoms and having a faithful sexual relationship with one partner reduces the transmission and contraction of HPV. 

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